The Key Extra Firm Hybrid Mattress, by Restonic, combines multiple layers of comfort foam with zoned, Individually Wrapped Coils, providing both a firm and supportive, sleep experience. A layer of Gel Infused Memory Foam provides extra support and a cooling effect. Featuring the Marvelous Middle®, a concentration of Individually Wrapped Coils in the center third of the mattress providing excellent support and reduced motion transfer. You'll experience full use of the mattress top with a Superedge Plus®, a firm foam encasement surrounding the mattress coils. Sleep well tonight on this exclusively made mattress.